The present invention relates to a road roller comprising a chassis frame, an encapsulated engine and a radiator through which cooling air flows.
Such road rollers are known, they being put to use more particularly on road construction sites. The radiator serves to cool the engine as well as a hydraulic system usually installed. In known road rollers the cooling air is drawn in from the side, from the front and/or from underneath, guided through the radiator and finally exhausted. For circulating the air a fan is normally employed which is fitted to the radiator.
It is often the case on known road rollers that the cooling air drawn into the system is dirty and dust-laden, the probability of this especially on construction sites being relatively high. The dust contained in the cooling air forms deposits in the engine compartment and radiator, resulting in the engine compartment being unecessarily soiled whilst simultaneously detrimenting the cooling effect of the radiator. In addition, difficulties may be experienced in servicing the hydraulic assemblies, due to this soilage, since contamination of the hydraulic fluid with dust needs to be avoided.
The present invention has thus the object of providing a supply of fresh air for cooling free of dust on such a road roller.
In accordance with the invention this object is achieved in a road roller of the aforementioned kind in that for guiding the cooling air a hood covering the engine incorporating an air intake and air outlet openings and a separate housing accommodating the radiator are provided, the hood and the housing being air-communicatingly connected.
Guiding the air in this way permits defined intake and exhaust of the cooling air. The cooling air is drawn in through the air intake of the hood only from above, i.e. from the substantially dust-free air above the road roller with no intake from underneath or from the side. The cooling air is then directed through the housing past the radiator back into the hood and exhausted through the air outlet openings of the hood, preferably in the direction of underside of the road roller, i.e. remote from the air intake to thus avoid a recirculation of the cooling air.
It is this air guiding system in accordance with the invention which considerably reduces soilage of the engine compartment and radiator, the cooling effect of which now remains substantially unchanged over lengthy periods. At the same time servicing the hydraulic assemblies is facilitated since the engine compartment remains substantially free of dust.
Advantageous further embodiments and aspects of the invention read from the sub-claims.
Preferably the hood comprises a fitting with an air intake in an air-flow connection via an opening with the housing accommodating the radiator. The fitting is closed off air-tight relative to the engine compartment covered by the hood. It is this design that ensures that the cooling air drawn into the system is not guided undirected through the hood, but instead from the fitting of the hood into the housing and subsequently to the radiator so that the complete air mass flow drawn into the system is thus made use of for cooling.
The hood comprises preferably an intake opening for the cooling air which is assigned an exhaust opening in the housing. The cooling air is drawn in from the environment into the fitting on the hood. From the fitting the cooling air gains access through an opening to the housing where it is deflected to flow through the radiator, before then passing through the exhaust opening of the housing and the intake opening back into the hood. The cooling air is thus drawn in, directed through and exhausted from the system all by defined porting.
In one advantageous aspect sidewalls are provided on the chassis frame beneath the hood for guiding the cooling air, the height of these sidewalls being less than that of the hood. Downstream of the radiator the cooling air flow is parted by the sidewalls within the hood. Part of the cooling air is immediately exhausted whilst another part continues to be guided between the sidewalls before being later exhausted. The cooling air gains access through the interspace between sidewalls and hood to the air outlet openings. It is this design that enhances the cooling effect. At the same time the encapsulation of the engine by the hood, housing and sidewalls achieves a reduction in the noise level.
Advantageously the hood comprises sideplates ported for cooling air exit, these ports providing defined air outlet openings for the cooling air. Any undesirable circulation of the cooling air, remaining in the engine compartment or exit at an undesirable location, especially in the vicinity of the air intake is reliably prevented.
Preferably the sidewalls are arranged spaced away from the sideplates and cover the outlet openings of the sideplates. The engine is encapsulated by the sidewalls to thus achieve a reduction in the noise level. The sidewalls also protect the engine from any dirt and dust entering the ports.
In another advantageous aspect the sidewalls extend from the radiator up to the end of the hood, as a result of which the complete engine compartment is laterally encapsulated by the sidewalls to further enhance a reduction in the noise level. At the same time any ingress of swirling dust-laden air into the engine compartment is again at least made difficult by the sidewalls.
Preferably the height of the sidewalls diminishes as of the radiator, they being configured roughly trapezoidal and laterally cover the ports in the sideplates of the hood to thus reliably protect the engine compartment from soilage. Diminishing the height of the sidewalls permits gaining access to the engine, when the hood is hinged up out of the way to faciliate maintenance work.
Advantageously the air intake comprises slots machined in the fitting of the hood which are speedy and cost-effective to produce. As an alternative a grille may be made use of.
In accordance with yet another further embodiment of the invention the hood is swivel-mounted on a chassis frame of the road roller. The housing accommodating the radiator is rigidly secured to this chassis frame. For maintenance work the hood may be hinged out of the way so that good access to the engine, radiator and hydraulic assemblies is assured. On completion of the maintenance work the hood is reclosed, the air guidance system in accordance with the invention then being instantly ready for operation without any further manipulation.